dm table: remove unused dm_get_device range parameters

Remove unused parameters(start and len) of dm_get_device()
and fix the callers.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index bd58703..e610725 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -80,8 +80,7 @@
 	if (sscanf(argv[1], "%llu", &start) != 1)
 		return -EINVAL;
 
-	if (dm_get_device(ti, argv[0], start, sc->stripe_width,
-			  dm_table_get_mode(ti->table),
+	if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
 			  &sc->stripe[stripe].dev))
 		return -ENXIO;